A CAI on a 5.0 liter V8 gives 20 whp h:

You'd be fortunate to get 20 whp from I/H/C/E. It's not unheard of, but most ppl don't expect such gains from a 1.8L 4-banger.

I'm not sure how valid the ads in magazine = biased magazine article. If that were the case 90% of the products tested in the magazines would fall under that category. Granted, they probably exagerrated the power gains but I don't trust everything I read from car mags anyways. Take it with a grain of salt. Maybe they had a fan on the dyno blowing iCy cOOl air with the engine hood popped and ice around the IM.

Shingo